Press button tuned radio receiver



June 2, 1942. w. PA'IZSCHKE ETAL 2,285,378

TREES BUTTON TIPNED RADIO RECEIVER Filed Sept. 7', 194i:

INVENTORS WILL] PATSCH/(E 513w! N16 7 l ATTORNEY Patented June 2, 1942 I 2,285,3'l8 PRESS nu'r'rou rrmsnname aEcErvna Willi Pataschke, Berlinezehlendorf, and Erwin Kiinig, Berlin-Wilmersdorf, Germany, assign ore to General Electric Company, a corporation of New York Application September 7, 190 Serial No. 355,722 In Germany July 27, 1939 1 Claim.

The invention is concerned with a press button tuned radio or Signaling apparatus comprising tuning coils which are capable of being cut in circuit or disconnected by the actuation of the press buttons. Now, according to the invention such apparatus are provided with an arrangement which in a simple manner insures tuning of the coils to different transmitters. For the purpose of tuning the coils, rotary knobs are provided preferably below the press button molding strip.

An exemplified embodiment according to the invention is shown in the appended drawing. Fig. 1 shows in -schematic form an arrangement according to the invention as applied to audio broadcast receiver apparatus. Fig. 2 illustrates a detailed viev: of an arrangement according to the invention, while Fig. 3 shows a top view of part thereof.

Referring to Fig. 1, 22 represents the push buttons. By pushing one of the press buttons the coils corr ponding thereto are cut in circuit, with the res t. that the apparatus picks up the transmitter to which the said coil is tuned. Below the press buttons 22 and placed slightly towards the rear are the rotary knobs I5 which allow the tuning coils to be tuned to any desired transmitter. Above the press buttons 22 and slightly recessed in the casing 24 is the scale 22.

Referring to Fig. 2, I and 2 denote the tuning coi1s, two thereof being tuned simultaneously each time. For instance, coil I belongs to the input circuit, while coil 2 belongs to the local oscillator. Coil I is tuned by means of the dustcore 3, while coil 2 is tuned bythe dust-core I. The said two dust-cores 3 and 4 are supported by a shaft 5 provided with a screw-thread. A non-magnetic spring 6 is clamped between the cores 3 and l, the said spring pressing the cores land 4 against the lock nuts I and 8. The shaft 5 is Journaled in the two end plates 9 and Ill of a tubular piece or sleeve II, each of the end plates being provided with a female screw-thread, so that when the shaft 5 is turned it is shifted in axial direction together with the dust cores 3 and 4. Tube or sleeve II serves at'the same time as the" support for the tuning coils I and 2 and is attached to a part I2 which is connected to the chassis of the apparatus. Shaft 5 passes through a bore-hole provided in part I2 and has arranged at its end a fixedly connected driving means iii. The latter comprises two arms or tappets by which it is driven bythe rotor ll upon the latter being rotated.

Rotor I has at its outer end a rotary knob l5 by means of which adjustment of the tuning coils is insured. Rotor I4 is joumaled in a bore-hole "5a of the front panel IS. A spiral spring I1 is clamped between the collar I8 of the rotor ll 7 and a washer disc I9 which presses against the inner surface of an enclosure member or mold .piece 20. The said. spring I! presses the rotor I4 against the molding I2 attached to the chassis of the apparatus. The end of the rotor near the coils is provided with slots. Through the slots 2i poject the arms of the driving means I3 so that upon rotation of the rotor I4 they are driven, while being capable of axial shift with respec to the rotor.

To the end of insuring simple mounting, the washer disc I8 is made elastical, while the inside diameter of the same is made equal to, or smaller than. the diameter of the rotary knob I! so that the washer disc II has only to be shifted over the rotary knob it during assembly. Such an arrangement is multiple in nature, indeed in the arrangement shown in Fig. 1. it is six-fold corresponding to the number of press buttons provided.

Now, the device operates as follows: By means of nut I or nut I the distance between the cores 2 and 4, for instance, by slots provided in the tube or sleeve II, is so adjusted that the coils I and 2 have the same inductance for each setting of the rotary knob Ii. has been attained then it is possible at any instant to adjust the various tuning coils by rotation of the rotary knobs I! so as to be tuned to any desired transmitter without the casing of the radio receiver apparatus having to be opened.

An arrangement according to the invention may be subsequently mounted in an apparatus if the shaft 5 were covered, for instance, by means of a protecting lid or cover, and after removal of the latter, was set, for instance, by means of a screw driver.

By an arrangement according to the invention the rotor I 4 is tensionally pressed in axial direction against the chassis of the apparatus so that rattling of the rotor H when being adjusted is precluded.

When mounting the chassis of the apparatus in the casing, it is generally impossible to avoid poor fit between the molding 30 and the front panel I6. However, by means of the spring Il rotor i4 is always held in tensional connection with molding It so that axial play of the rotary knob II is obviated.

Once this condition 'We claim:

In 'a tuningassembiy, a main panel and a subpanel arranged in spaced parallel relation and provided with coaxial openings, an axially adiustable shaft mounted substantially normal to said panel and having one end thereof protrud in: through the sub-panel opening, a plurality oi cores slidably and coaxially mountedon said shaft, resilient means acti'ngupon said cores and tending to force the cores apart in an axial direction, adjustable stops mounted on said shaft andv and having a portion-mounted within the opening of the main panel and provided with a keyway into which said up-turned element is fitted,

said'operating means having a portion which pro-. trudes an appreciable distance beyond the outer face oi said main panel, an enclosure member mounted on the outer face of said main panel for covering the opening therein, said enclosure member being provided with an opening through which the protruding portion of the operating means extends, and resilient means interposed between the panel side of the member and the operating means for holding the latter-means tightly against the sub-panel.

WILLI PATZSCHKE. ERWIN KGNIG. 

